Write a LEX program that reads c program from input file and writes same program to output file appending line number to every line other than comment.

               Code :

%{

#include<stdio.h>

int cnt=1;

%}

%%

\/\/.*  {fprintf(yyout,"");}

\/\*(.*\n)*.*\*\/ {fprintf(yyout,"");}

.* {fprintf(yyout,"%d %s",cnt,yytext);

                 cnt++;}

%%

main()

{

    yyin=fopen("input.txt","r");

    yyout=fopen("output.txt","w");

     yylex();

}

int yywrap()

{

return 1;

}